Helical Piles and Helical Piers in San Francisco, Marin and the Bay Area
When soft soils, tight access, or a nearby building make conventional foundations slow or risky, helical piles are often the better answer. LVI Engineering installs helical piles (also called helical piers or screw piles) for new foundations, underpinning, and earth-retention tiebacks across San Francisco, Marin County, the East Bay, and Northern California. They install quickly and quietly, and their capacity can be verified on site.
Looking for a contractor who can take your project from demolition to foundation?
A helical pile is a steel shaft with one or more helix-shaped bearing plates welded near the tip. A hydraulic torque motor on an excavator or smaller rig screws the pile into the ground, adding extension sections until the helices reach the bearing layer the design calls for. The load then transfers from the structure, through the shaft, to the helices bearing in competent soil, bypassing weak surface soils.
Because the pile is screwed in rather than driven or drilled, there’s no spoil to haul off, very little vibration, and no concrete cure time. Piles can usually take load as soon as they’re installed and capped.
The California Building Code recognizes helical piles as a deep foundation type. Product systems are commonly evaluated under ICC-ES acceptance criteria (AC358). Your structural and geotechnical engineers set the required capacities, and we install to that design.
Where Helical Piles Make Sense
New Foundations
Helical piles support new homes, additions, commercial buildings, light industrial structures, decks, canopies, signs, equipment pads, and modular buildings. They work especially well where soft or variable soils would otherwise call for over-excavation or deep drilled piers.
Foundation Underpinning and Repair
Helical piles can be installed next to an existing footing and tied into it with a bracket, stabilizing a settling foundation or supporting it ahead of nearby excavation. This is common in older San Francisco and Marin buildings and alongside new shoring and excavation work.
Tiebacks and Earth Retention
Installed at an angle, helical anchors serve as tiebacks for retaining walls and excavation shoring, as an alternative to grouted anchors in suitable soils.
Tight-Access and Sensitive Sites
Compact rigs reach backyards, crawlspaces, hillside lots, and interior spaces that drill rigs can’t. Low vibration matters next to older masonry buildings, occupied spaces, and sensitive equipment.
Uplift and Lateral Loads
Helical piles resist tension well, which helps with wind uplift, seismic overturning, and lightweight structures.
Why Helical Piles Work in Bay Area Soils
Bay mud and soft fill. Along the waterfront, Mission Bay, the Bayshore corridor, and low-lying Marin and East Bay areas, helical piles can extend through compressible soils to a firmer bearing layer without large excavations or dewatering.
Dune sand. In western San Francisco, caving sand can complicate drilled piers. A screwed-in steel shaft avoids open holes.
Hillsides. In Mill Valley, Sausalito, the Oakland and Berkeley hills, and other steep areas, small rigs and modular sections make it practical to build where access is limited.
High groundwater. With no open hole to keep dry, there’s no need for tremie concrete or casing in many cases.
Helical piles aren’t right for every site. Very dense gravels, cobbles, debris-laden fill, or shallow rock can limit penetration. A geotechnical investigation should confirm they’re appropriate, and we’re glad to review the report with you before you commit.
Helical Piles vs. Drilled Piers
Helical piles
Drilled concrete piers
Spoils
Little to none
Drill cuttings to haul off
Vibration and noise
Low
Moderate
Cure time
Can be loaded after installation and capping
Concrete must cure
Groundwater / caving
Generally unaffected
May need casing or tremie placement
Access
Compact equipment available
Larger drill rig typically required
Capacity verification
Installation torque recorded on every pile; load testing as specified
Relies on design and inspection; testing less common
Your engineer will choose based on loads, soils, and cost. Bringing us in during preconstruction lets the team compare options early.
Our Helical Pile Process
Review the design and geotechnical data. We confirm pile locations, required capacities, target depths, and any load-test requirements with the engineer of record.
Locate utilities and plan access. We call 811 and coordinate private locating, then plan equipment access and protect the existing site.
Install and monitor torque. Each pile goes in to the design depth and torque criteria. Installation torque correlates with capacity, so we record it for every pile and submit installation logs.
Load testing (as specified). We coordinate compression or tension tests where the design or jurisdiction requires them.
Cut, cap and connect. We cut piles to elevation and install caps or brackets, then hand off to concrete or framing, or perform the foundation concrete ourselves.
One Contractor From Demo to Foundation
LVI Engineering is a general engineering contractor that also handles demolition, excavation, grading, shoring, soil nails, utility installation, and concrete. On many projects, helical piles are one piece of a bigger site and foundation scope. Having one team carry that scope keeps the schedule tight and the responsibility clear.
Helical Pile FAQs
How deep do helical piles go?
As deep as needed to reach the bearing layer and installation torque the design specifies. Depth is set by the geotechnical and structural engineers and confirmed in the field.
Are helical piles permanent?
Yes. When designed for the site’s soil corrosivity (for example, with galvanized steel and corrosion allowances), helical piles are permanent deep foundations.
Can helical piles be installed inside an existing building?
Often, yes. Compact, low-headroom equipment can install piles in crawlspaces, basements, and interiors for underpinning and retrofit work.
Have a design, a geotechnical report, or just a tricky site? Send us what you have, and we’ll tell you whether helical piles fit and what they would involve.
